Hypertension and Pregnancy
Hypertension is a condition where the pressure of blood against the blood vessel wall is high. Blood pressure is measured in two numbers; upper and lower. The normal blood pressure reading is less than 120 (upper reading)/80 (lower reading) mm Hg. You have hypertension if your blood pressure readings are ≥130/90 mm Hg.
Hypertension is a common disorder affecting every one in four Canadians. It is also common in pregnancy, affecting almost 7% of pregnancies. Hypertension during pregnancy may be a severe concern for some females as it may cause some complications for the developing baby and mother. But when well-managed, it is not always dangerous.
So, if you have hypertension and planning to get pregnant or are pregnant, talk to your doctor and figure out the best way to cure hypertension and prevent high blood pressure-related complications.
Table of Contents
Changes in Blood Pressure during Pregnancy
Before moving ahead, let us understand why pregnant women are at a higher risk of hypertension.
Some reasons for the same are:
- According to the Journal Circulation, blood volume may increase by 45% during pregnancy. This additional blood volume causes the heart to work more to pump this blood throughout the body.
- The extra blood causes the left side of the heart to become thicker and larger. These changes support your heart to work harder.
- During pregnancy, the kidney produces extra amounts of vasopressin that promotes water retention.
In the majority of the cases, blood pressure returns back to normal levels after delivery. If this does not happen, your doctor may prescribe medications to get your blood pressure level under control.
What is considered as High Blood Pressure during Pregnancy?
To find out “normal” blood pressure during pregnancy, your doctor will check your baseline pressure during your first visit. They will also check your pressure levels in all consequent visits.
- Normal blood pressure: Anything less than 120/80 mm Hg.
- High blood pressure: ≥130/90 mm Hg.
Besides, upper number ≥ 140 mm Hg and/or lower number ≥90 mm Hg is also considered as high blood pressure during pregnancy. If your blood pressure is 15 degrees higher on the upper number from the baseline, it may be a cause of concern.
However, early in pregnancy, from five weeks to the middle of the second trimester, your blood pressure may decrease. This is because of pregnancy hormones that widen your blood vessels, and thus resistance to blood flow is not much.
How to Monitor Blood Pressure during Pregnancy?
While your doctor will check your pressure levels during each visit, you also need to monitor it between doctor visits.
Here is how you can do that:
- Get a blood pressure monitor from an online medical store or pharmacy.
- To check for the machine’s accuracy, take it to the doctor’s office and compare the readings with those from your doctor.
- For accurate readings, measure blood pressure at the same time every day.
- Check blood pressure while sitting straight, in a silent room, and legs uncrossed.
- Use the same arm every day.
Alternatively, you can also visit a pharmacy or a grocery store with a blood pressure measuring machine. If you notice repeated high blood pressure readings, notify your doctor immediately.
Types of Pregnancy-Related Hypertensive Conditions
Hypertension during pregnancy can be of following three different types:
When you have hypertension before getting pregnant, the condition is known as chronic hypertension. According to experts, hypertension occurring in the first 20 weeks of pregnancy is also considered as chronic hypertension.
It is generally managed with blood pressure-lowering medications.
This type of high blood pressure develops after the 20th week of pregnancy. However, if hypertension develops after the 30th week of pregnancy, it has a greater risk of progressing to preeclampsia (explained below).
It may also lead to preterm labor or low birth weight.
The doctor will monitor your condition throughout pregnancy to prevent complications. Gestational hypertension generally resolves after delivery.
Pregnant women with high blood pressure before pregnancy may develop preeclampsia. In this condition, along with high blood pressure, pregnant women experience kidney problems with protein in the urine.
If left unattended, it may cause severe complications for both mother and the baby. Your doctor will monitor you closely throughout pregnancy to prevent preeclampsia related complications.
Various causes can increase your blood pressure during pregnancy. Some of them are:
- Being obese or overweight
- Sedentary lifestyle
- Alcohol consumption
- Carrying more than one child
- First-time pregnancy
- Family history of hypertension during pregnancy
- Above 35 years of age
- Having autoimmune disorders or diabetes
- Assistive reproductive technology such as in vitro fertilization (IVF)
Many factors play a role in developing hypertension during pregnancy.
Type of Pregnancy
It is seen that women getting pregnant for the first time are at a higher risk of high blood pressure. Fortunately, the risk of hypertension in subsequent pregnancies is less.
Besides, carrying more than one baby also increases the risk of hypertension as the body has to work harder to nurture more than one baby.
According to the American Society for Reproductive Medicine IVF and other assistive technologies increase the risk of high blood pressure.
Being obese or overweight, an unhealthy lifestyle, or not staying active also increase the risk of hypertension.
Women above 35 years of age are at a higher risk of high blood pressure during pregnancy.
Women with hypertension have a higher risk of the following complications:
Preeclampsia, also known as toxemia, is a severe condition that may damage your kidneys and brain. If left unattended, preeclampsia can progress to a state with seizures, known as eclampsia.
Symptoms of preeclampsia are:
- Persistent headaches
- Upper abdominal pain
- Difficulty in breathing
- Swelling of face and hands
- Changes in vision or seeing spots
- Vomiting or nausea later in pregnancy
As preeclampsia may be dangerous for you and your baby, you should contact your doctor immediately if you notice any of the mentioned symptoms. Besides, regular doctor visits will help your doctor monitor you and catch preeclampsia early.
HELLP, which stands for hemolysis, elevated liver enzymes, and low platelet count. It can occur as a complication of preeclampsia and is a life-threatening condition.
Symptoms of HELLP are:
- Upper abdominal pain
HELLP may cause significant damage to the vital organs, and emergency care includes lowering blood pressure. In some cases, preterm delivery may be needed.
Hypertension during pregnancy may also alter the baby’s growth rate, resulting in low birth weight.
According to the American Congress of Obstetricians and Gynecologists complications can include:
- Preterm delivery, which is delivery before 38 weeks of pregnancy.
- Placental abruption, a condition where the placenta separates from the uterus. It is a medical emergency.
- Cesarean delivery
Preventing Hypertension during Pregnancy
Here are lifestyle modifications to prevent high blood pressure during pregnancy:
- Maintain weight
- Eat healthily
- Avoid drinking alcohol and smoking
- Limit salt intake
- Being active
Besides, pregnancy causes hormonal shifts that may result in physical and psychological changes. This may cause stress that may make it difficult to manage hypertension you can try stress-relieving techniques such as meditation and yoga. Managing anxiety is of vital importance in patients have symptoms of asthma, hypertension etc.
Read more about asthma and anxiety here.
While many traditional blood pressure reducing medications are not safe during pregnancy, labetalol and methyldopa are considered safe.
Medications that are not recommended during pregnancy:
- ACE inhibitors
- Angiotensin receptor blockers
These drugs pass to the baby through the bloodstream and negatively impact the baby. Your doctor will select a single or a combination of medications to manage hypertension based on your condition.
Hypertension is a common occurrence during pregnancy, affecting almost 7% of pregnant women. If left untreated, it may cause complications for both mother and the baby.
Hypertensive disorders are a leading cause of maternal death, and it is thus important to talk to your physician about any concerns. Be cautious and make necessary lifestyle changes that can help in lowering the risk of developing hypertension-related complications.